Shimano EW-JC304 4-Port Di2 Junction (Black)

This frame junction box connects via SD300 E-tube wires to four different points: front derailleur, rear derailleur, cockpit junction and battery mount.

Note: This is designed for use with Shimano SD300 E-tube wires, which are used on the current 12 speed road groupsets and Shimano EP8 ebike systems.